vis

vis.1

(33327B)

 .Dd January 14, 2017
 .Dt VIS 1
 .Os Vis VERSION
 .
 .Sh NAME
 .
 .Nm vis
 .Nd a highly efficient text editor
 .
 .Sh SYNOPSIS
 .
 .Nm
 .Op Fl v
 .Op Cm + Ns Ar command
 .Op Fl -
 .Op Ar files ...
 .
 .Sh DESCRIPTION
 .
 .Nm
 is a highly efficient screen-oriented text editor combining the strengths of
 both
 .Nm vi(m)
 and
 .Nm sam .
 .
 This manual page is intended for users already familiar with
 .Nm vi Ns / Ns Nm sam .
 Anyone else should almost certainly read a good tutorial on either editor
 before this manual page.
 The following options are available:
 .Bl -tag -width indent
 .It Fl v
 Print version information and exit.
 .It Cm + Ns Ar command
 Execute
 .Ar command
 after loading file.
 .
 .It Fl -
 Denotes the end of the options.
 Arguments after this will be handled as a
 file name.
 .El
 .Pp
 The special file
 .Cm -
 instructs
 .Nm
 to read from standard input in which case
 .Ic :wq
 will write to standard output, thereby enabling usage as an interactive filter.
 .Pp
 If standard input is redirected and all input is consumed,
 .Nm
 will open
 .Pa /dev/tty
 to gather further commands.
 Failure to do so results in program termination.
 .
 .Ss Selections
 .
 .Nm
 uses selections as core editing primitives.
 A selection is a non-empty, directed range with two endpoints called
 .Em cursor
 and
 .Em anchor .
 A selection can be anchored in which case the anchor remains fixed while
 only the position of the cursor is adjusted.
 For non-anchored selections both endpoints are updated.
 A singleton selection covers one character on which both cursor and
 anchor reside.
 There always exists a primary selection which remains visible
 (i.e. changes to its position will adjust the viewport).
 .
 .Ss Modes
 .
 .Nm
 employs the same
 .Em modal
 editing approach as
 .Nm vi .
 It supports a
 .Sq normal ,
 .Sq operator pending ,
 .Sq insert ,
 .Sq replace
 and
 .Sq visual
 (in both line and character wise variants) mode.
 The visual block and ex modes are deliberately not implemented,
 instead
 .Nm
 has built in support for multiple selections and an
 .Em interactive
 variant of the structural regular expression based command language of
 .Nm sam .
 .Pp
 In normal mode all selections are non-anchored and reduced to a single character.
 .
 .Ss Undo/Redo
 .
 .Nm
 uses an undo tree to keep track of text revisions.
 The
 .Ic u
 .Pq undo
 and
 .Aq Ic C-r
 .Pq redo
 commands can be used to traverse the tree along the main branch.
 .Ic g+
 and
 .Ic g-
 traverse the history in chronological order.
 The
 .Ic :earlier
 and
 .Ic :later
 commands provide means to restore the text to an arbitrary state.
 .
 .Ss Marks
 .
 A mark associates a symbolic name to a set of selections.
 A stored selection becomes invalid when its delimiting boundaries change
 in the underlying buffer.
 If said changes are later undone the mark becomes valid again.
 .Ic m
 sets a mark,
 .Ic M
 restores it.
 For example,
 .Ic ' Ns Ar a Ns Ic m
 sets the mark
 .Ar a
 while
 .Ic ' Ns Ar a Ns Ic M
 restores it.
 Use of
 .Ic m
 or
 .Ic M
 without specifying a mark uses the default mark.
 .Pp
 Available marks are:
 .Bl -tag -width indent
 .It Ic ''
 default mark
 .It Ic '^
 active selections when leaving visual mode
 .It Ic 'a Ns \(en Ns Ic 'z
 general purpose marks
 .El
 .Pp
 No marks across files are supported.
 Marks are not preserved over editing sessions.
 .
 .Ss Jump list
 .
 A per window, fixed sized file local jump list exists which stores marks
 (i.e. set of selections).
 .Bl -tag -width indent
 .It Ic g<
 jump backward
 .It Ic g>
 jump forward
 .It Ic gs
 save currently active selections
 .El
 .
 .Ss Registers
 .
 Registers are named lists of text.
 Uninitialized register slots default to the empty string.
 Available registers are:
 .Bl -tag -width indent
 .It Ic \(dq\(dq
 default register
 .It Ic \(dqa Ns \(en Ns Ic \(dqz
 general purpose registers
 .It Ic \(dqA Ns \(en Ns Ic \(dqZ
 append to corresponding general purpose register
 .It Ic \(dq* , Ic \(dq+
 system clipboard integration via shell script
 .Xr vis-clipboard 1
 .It Ic \(dq0
 yank register, most recently yanked range
 .It Ic \(dq1 Ns \(en Ns Ic \(dq9
 .It Ic \(dq&
 sub expression matches of most recent
 .Ic x
 or
 .Ic y
 command
 .It Ic \(dq/
 search register, most recently used search pattern
 .It Ic \(dq\&:
 command register, most recently executed command
 .It Ic \(dq_
 black hole
 .Pq Pa /dev/null
 register, ignore content is always empty
 .It Ic \(dq#
 selection number (readonly)
 .El
 .Pp
 If no explicit register is specified the default register is used.
 .
 .Ss Macros
 .
 The general purpose registers
 .Ic \(dqa Ns \(en Ns Ic \(dqz
 can be used to record macros.
 Use one of
 .Ic \(dqA Ns \(en Ns Ic \(dqZ
 to append to an existing macro.
 .Ic q
 starts a recording,
 .Ic @
 plays it back.
 .Ic @@
 refers to the most recently recorded macro.
 .Ic @:
 repeats the last
 .Ic \&: Ns -command.
 .Ic @/
 is equivalent to
 .Ic n
 in normal mode.
 .
 These operations always use the first register slot.
 .
 .Ss Encoding, Tab and Newline handling
 .
 .Nm
 always assumes the input file to be UTF-8 encoded with
 .Li \[rs]n
 line endings.
 If you wish to edit files with legacy encodings or non-Unix line endings,
 use
 .Xr iconv 1
 and
 .Xr dos2unix 1
 to convert them as needed.
 .Aq Ic Tab
 can optionally be expanded to a configurable number of spaces (see
 .Sx "SET OPTIONS" ) .
 .
 .Ss Mouse support
 .
 The mouse is currently not used at all.
 .
 .Sh SAM COMMANDS
 .
 .Nm
 supports an interactive variant of the structural regular expression based
 command language introduced by
 .Xr sam 1 .
 .
 .Ss Regular expressions
 .
 .Nm
 currently defers regular expression matching to the underlying C library.
 It uses what POSIX refers to as
 .Dq Extended Regular Expressions
 as described in
 .Xr regex 7 .
 The anchors
 .Ic ^
 and
 .Ic $
 match the beginning / end of the range they are applied to.
 Additionally
 .Li \[rs]n
 and
 .Li \[rs]t
 may be used to refer to newlines and tabs,
 respectively.
 The
 .Ic \&.
 atom matches any character except newline.
 The empty regular expression stands for the last complete expression
 encountered.
 .
 .Ss Addresses
 .
 An address identifies a substring (or range) in a file.
 In the following
 .Do
 character
 .Ar n
 .Dc
 means the null string after the
 .Ar n Ns -th
 character in the file, with 1 the first character in the file.
 .Do
 Line
 .Ar n
 .Dc
 means the
 .Ar n Ns -th
 match, starting at the beginning of the file, of the regular expression
 .Dq Li .*\[rs]n\&? .
 .Pp
 All windows always have at least one current substring which is the default
 address.
 In sam this is referred to as
 .Sy dot .
 In
 .Nm
 multiple
 .Dq dots
 (or selections) can exist at the same time.
 .
 .Ss Simple addresses
 .
 .Bl -tag -width indent
 .It Ic # Ns Ar n
 The empty string after character
 .Ar n ;
 .Ic #0
 is the beginning of the file.
 .It Ar n
 Line
 .Ar n .
 .It Ic / Ns Ar regexp Ns Ic /
 .It Ic \&? Ns Ar regexp Ns Ic \&?
 The substring that matches the regular expression, found by looking
 towards the end
 .Pq Ic /
 or beginning
 .Pq Ic \&?
 of the file.
 The search does not wrap around when hitting the end
 .Pq start
 of the file.
 .It Ic 0
 The string before the first full line.
 This is not necessarily the null string; see
 .Ic +
 and
 .Ic -
 below.
 .It Ic $
 The null string at the end of the file.
 .It Ic \&.
 Dot, the current range.
 .It Ic ' Ns Ar m
 The mark
 .Ar m
 in the file.
 .El
 .
 .Ss Compound addresses
 .
 In the following,
 .Ar a1
 and
 .Ar a2
 are addresses.
 .Bl -tag -width indent
 .It Ar a1 Ns Ic + Ns Ar a2
 The address
 .Ar a2
 evaluated starting at the end of
 .Ar a1 .
 .It Ar a1 Ns Ic - Ns Ar a2
 The address
 .Ar a2
 evaluated looking the reverse direction starting at the beginning of
 .Ar a1 .
 .It Ar a1 Ns Ic \&, Ns Ar a2
 The substring from the beginning of
 .Ar a1
 to the end of
 .Ar a2 .
 If
 .Ar a1
 is missing,
 .Ic 0
 is substituted.
 If
 .Ar a2
 is missing,
 .Ic $
 is substituted.
 .It Ar a1 Ns Ic \&; Ns Ar a2
 Like
 .Ar a1 Ns Ic \&, Ns Ar a2
 but with
 .Ar a2
 evaluated at the end of, and range set to,
 .Ar a1 .
 .El
 .Pp
 The operators
 .Ic +
 and
 .Ic -
 are high precedence, while
 .Ic \&,
 and
 .Ic \&;
 are low precedence.
 .Pp
 In both
 .Ic +
 and
 .Ic -
 forms, if
 .Ar a2
 is a line or character address with a missing number, the number defaults to 1.
 If
 .Ar a1
 is missing,
 .Ic \&.
 is substituted.
 If both
 .Ar a1
 and
 .Ar a2
 are present and distinguishable,
 .Ic +
 may be elided.
 .Ar a2
 may be a regular expression; if it is delimited by
 .Li \&?
 characters, the effect of the
 .Ic +
 or
 .Ic -
 is reversed.
 .
 The
 .Ic %
 sign is an alias for
 .Ic \&,
 and hence
 .Ic 0,$ .
 .
 It is an error for a compound address to represent a malformed substring.
 .
 .Ss Commands
 .
 In the following, text demarcated by slashes represents text delimited
 by any printable ASCII character except alphanumerics.
 Any number of trailing delimiters may be elided, with multiple elisions then
 representing null strings, but the first delimiter must always be present.
 In any delimited text, newline may not appear literally;
 .Li \[rs]n
 and
 .Li \[rs]t
 may be typed for newline and tab;
 .Li \[rs]/
 quotes the delimiter, here
 .Li / .
 An ampersand
 .Li &
 and
 .Li \[rs] Ns Ar n ,
 where
 .Ar n
 is a digit (1\(en9) are replaced by the corresponding register.
 Backslash is otherwise interpreted literally.
 .Pp
 Most commands may be prefixed with an address to indicate their range of
 operation.
 If a command takes an address and none is supplied, a default address is used.
 In normal mode this equates to the character the selection is currently over.
 If only one selection exists
 .Ic x
 and
 .Ic y
 default to the whole file
 .Ic 0,$ .
 In normal mode the write commands
 .Ic w
 and
 .Ic wq
 always apply to the whole file.
 Commands are executed once for every selection.
 In visual mode the commands are applied to every selection
 as if an implicit
 .Ic x
 command, matching the existing selections, was present.
 .
 .Pp
 In the description,
 .Dq range
 is used to represent whatever address is supplied.
 .Pp
 Many commands create new selections as a side effect when issued from a visual
 mode.
 If so, it is always to the “result” of the change: the new text for an
 insertion, the empty string for a deletion, the command output of a filter etc.
 If after a successful command execution no selections remain,
 the editor will switch to normal mode, otherwise it remains in
 visual mode.
 This allows
 .Em interactive
 refinements of ranges.
 .
 .\" Many commands set the value of dot as a side effect.
 .\" If so, it is always to the
 .\" .Dq result
 .\" of the change: the empty string for a deletion, the new text for an
 .\" insertion, etc.
 .\" .Po
 .\" but see the
 .\" .Sy s
 .\" and
 .\" .Sy e
 .\" commands
 .\" .Pc .
 .
 .Ss Text commands
 .
 .Bl -tag -width indent
 .It Ic a Ns [ Ar count ] Ns / Ns Ar text Ns Ic /
 Insert the
 .Ar text
 .Ar count
 times into the file after the range.
 .\" Set dot.
 .Pp
 May also be written as
 .Bd -literal -offset indent
  a
  lines
  of
  text
  .
 .Ed
 .
 .It Ic c No or Ic i
 Same as
 .Ic a ,
 but
 .Ic c
 replaces the text, while
 .Ic i
 inserts
 .Em before
 the range.
 .
 .It Ic d
 Delete the text in range.
 .\" Set dot.
 .El
 .
 .Ss Display commands
 .
 .Bl -tag -width Ds
 .It Ic p
 Create a new selection for the range.
 .El
 .
 .Ss I/O commands
 .
 .Bl -tag -width indent
 .It Ic e Ns Oo Cm \&! Oc Op Pa file name
 Replace the file by the contents of the named external file.
 If no file name is given, reload file from disk.
 .
 .It Ic r Ar file name
 Replace the text in the range by the contents of the named external file.
 .\" Set dot.
 .
 .It Ic w Ns Oo Cm \&! Oc Op Ar file name
 Write the range
 .Po
 default
 .Ic 0,$
 .Pc
 to the named external file.
 .
 .It Ic wq Ns Oo Cm \&! Oc Op Ar file name
 Same as
 .Ic w ,
 but close file afterwards.
 .El
 .Pp
 If the file name argument is absent from any of these, the current file name is
 used.
 .
 .Ic e
 always sets the file name,
 .Ic w
 will do so if the file has no name.
 Forcing the
 .Ic e
 command with
 .Cm \&!
 will discard any unsaved changes.
 Forcing
 .Ic w
 will overwrite the file on disk even if it has been externally modified
 since loading it.
 Write commands with a non-default addresses and no file name are destructive
 and need always to be forced.
 .Bl -tag -width indent
 .
 .It Ic < Ar shell command
 Replace the range by the standard output of the shell command.
 .
 .It Ic > Ar shell command
 Sends the range to the standard input of the shell command.
 .
 .It Ic \&| Ar shell command
 Send the range to the standard input, and replace it by the standard output, of
 the shell command.
 .
 .It Ic \&! Ar shell command
 Run interactive shell command, redirect keyboard input to it.
 .
 .It Ic cd Ar directory
 Change working directory.
 If no directory is specified,
 .Ev "$HOME"
 is used.
 .El
 .Pp
 In any of
 .Ic < ,
 .Ic > ,
 .Ic \&| ,
 or
 .Ic \&! ,
 if the shell command is omitted, the last shell command
 .Pq of any type
 is substituted.
 Unless the file being edited is unnamed, all these external commands
 can refer to its absolute path and file name through the
 .Ev vis_filepath
 and
 .Ev vis_filename
 environment variables.
 .
 .Ss Loops and conditionals
 .
 .Bl -tag -width indent
 .It Ic x/ Ns Ar regexp Ns Ic / Op Ar command
 For each match of the regular expression in the range, run the command with
 range set to the match.
 If the regular expression and its slashes are omitted,
 .Ar "/.*\[rs]n/"
 is assumed.
 Null string matches potentially occur before every character of the range and
 at the end of the range.
 .Pp
 The
 .Ic \(dq1 Ns \(en Ns Ic \(dq9
 and
 .Ic \(dq&
 registers are updated with the (sub) expression matches of the pattern.
 .
 .It Ic y/ Ns Ar regexp Ns Ic / Op Ar command
 Like
 .Ic x ,
 but run the command for each substring that lies before, between, or after the
 matches that would be generated by
 .Ic x .
 There is no default behavior.
 Null substrings potentially occur before every character in the range.
 .
 .It Ic X/ Ns Ar regexp Ns Ic "/" Ar command
 For each file whose file name matches the regular expression, make that the
 current file and run the command.
 If the expression is omitted, the command is run in every file.
 .
 .It Ic Y/ Ns Ar regexp Ns Ic / Ar command
 Same as
 .Ic X ,
 but for files that do not match the regular expression, and the expression is
 required.
 .\" TODO improve markup, use Op macro, make it actually understandable :/
 .It Ic g Ns [ Ar count ] Ns [ Ar /regexp/ ] Ar command
 .It Ic v Ns [ Ar count ] Ns [ Ar /regexp/ ] Ar command
 If the
 .Ar count
 range contains
 .Po
 .Ic g
 .Pc
 or does not contain
 .Po
 .Ic v
 .Pc
 a match for the expression, run command on the range.
 .Pp
 The
 .Ar count
 specifier has the following format, where
 .Ar n
 and
 .Ar m
 are integers denoting the ranges.
 .Bl -tag -width indent
 .It Ar n Ns Ic \&, Ns Ar m
 The closed interval from
 .Ar n
 to
 .Ar m .
 If
 .Ar n
 is missing,
 .Ic 1
 is substituted.
 If
 .Ar m
 is missing,
 .Ic ∞
 is substituted.
 Negative values are interpreted relative to the last range.
 .It Ic % Ns Ar n
 Matches every
 .Ar n Ns -th
 range.
 .El
 .
 .El
 .Pp
 These may be nested arbitrarily deeply.
 An empty command in an
 .Ic x
 or
 .Ic y
 defaults to
 .Ic p .
 .Ic X ,
 .Ic Y ,
 .Ic g
 and
 .Ic v
 do not have defaults.
 .
 .Ss Grouping and multiple changes
 .
 Commands may be grouped by enclosing them in curly braces.
 Semantically, the opening brace is like a command: it takes an
 .Pq optional
 address and runs each sub-command on the range.
 Commands within the braces are executed sequentially, but changes
 made by one command are not visible to other commands.
 .Pp
 When a command makes a number of changes to a file, as in
 .Ic x/ Ns Ar re Ns Ic / Ic c/ Ns Ar text Ns Ic / ,
 the addresses of all changes are computed based on the initial state.
 If the changes are non-overlapping, they are applied in the specified
 order.
 Conflicting changes are rejected.
 .Pp
 Braces may be nested arbitrarily.
 .
 .Sh VI(M) KEY BINDINGS
 .
 In the following sections angle brackets are used to denote special keys.
 The prefixes
 .Ic C- ,
 .Ic S- ,
 and
 .Ic M-
 are used to refer to the
 .Aq Ctrl ,
 .Aq Shift
 and
 .Aq Alt
 modifiers, respectively.
 .Pp
 All active key bindings can be listed at runtime using the
 .Ic :help
 command.
 .
 .Ss Operators
 .
 Operators perform a certain operation on a text range indicated by either a
 motion, a text object or an existing selection.
 .Pp
 When used in normal mode, the following operators wait for a motion, putting
 vis into operator pending mode.
 .Bl -tag -width XXXXXXXXXX -compact
 .It Ic c
 change, delete range and enter insert mode
 .
 .It Ic d
 delete, cut range to register
 .
 .It Ic <
 shift-left, decrease indent
 .
 .It Ic >
 shift-right, increase indent
 .
 .It Ic y
 yank, copy range to register
 .El
 .Pp
 When used in normal mode, the following actions take effect immediately.
 .Bl -tag -width XXXXXXXXXX -compact
 .It Ic =
 format, filter range through
 .Xr fmt 1
 .
 .It Ic gu
 make lowercase
 .
 .It Ic gU
 make uppercase
 .
 .It Ic g~
 swap case
 .
 .It Ic J
 join lines, insert spaces in between
 .
 .It Ic gJ
 join lines remove any delimiting white spaces
 .
 .It Ic p
 put register content after cursor
 .
 .It Ic P
 put register content before cursor
 .
 .El
 .
 .Ss Motions
 .
 .\" TODO? more formal definition: pos -> [min(pos, f(pos)), max(pos, f(pos))]
 Motions take an initial file position and transform it to a destination file
 position,
 thereby defining a range.
 .\" TODO define word/WORD
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .It Ic 0
 start of line
 .
 .It Ic b
 previous start of a word
 .
 .It Ic B
 previous start of a WORD
 .
 .It Ic $
 end of line
 .
 .It Ic e
 next end of a word
 .
 .It Ic E
 next end of a WORD
 .
 .It Ic F Ns Aq Ar char
 to next occurrence of
 .Aq Ar char
 to the left
 .
 .It Ic f Ns Aq Ar char
 to next occurrence of
 .Aq Ar char
 to the right
 .
 .It Ic ^
 first non-blank of line
 .
 .It Ic g0
 begin of display line
 .
 .It Ic g$
 end of display line
 .
 .It Ic ge
 previous end of a word
 .
 .It Ic gE
 previous end of a WORD
 .
 .It Ic gg
 begin of file
 .
 .It Ic G
 goto line or end of file
 .
 .It Ic gj
 display line down
 .
 .It Ic gk
 display line up
 .
 .It Ic gh
 codepoint left
 .
 .It Ic gl
 codepoint right
 .
 .It Ic gH
 byte left
 .
 .It Ic gL
 byte right
 .It Ic g_
 last non-blank of line
 .
 .It Ic gm
 middle of display line
 .
 .It Ic g\&|
 goto column
 .
 .It Ic h
 char left
 .
 .It Ic H
 goto top/home line of window
 .
 .It Ic j
 line down
 .
 .It Ic k
 line up
 .
 .It Ic l
 char right
 .
 .It Ic L
 goto bottom/last line of window
 .
 .It Ic %
 match bracket, quote or backtick
 .
 .It Ic }
 next paragraph
 .
 .It Ic \&)
 next sentence
 .
 .It Ic N
 repeat last search backwards
 .
 .It Ic n
 repeat last search forward
 .
 .It Ic [{
 previous start of block
 .
 .It Ic ]}
 next start of block
 .
 .It Ic [(
 previous start of parentheses pair
 .
 .It Ic ])
 next start of parentheses pair
 .
 .It Ic {
 previous paragraph
 .
 .It Ic \&(
 previous sentence
 .
 .It Ic \&;
 repeat last to/till movement
 .
 .It Ic \&,
 repeat last to/till movement but in opposite direction
 .
 .It Ic #
 search word under selection backwards
 .
 .It Ic *
 search word under selection forwards
 .
 .It Ic T Ns Aq Ar char
 till before next occurrence of
 .Aq Ar char
 to the left
 .
 .It Ic t Ns Aq Ar char
 till before next occurrence of
 .Aq Ar char
 to the right
 .
 .It Ic \&? Ns Ar pattern
 to next match of
 .Ar pattern
 in backward direction
 .
 .It Ic / Ns Ar pattern
 to next match of
 .Ar pattern
 in forward direction
 .
 .It Ic w
 next start of a word
 .
 .It Ic W
 next start of a WORD
 .El
 .
 .Ss Text objects
 .
 .\" TODO? more formal definition: text-object: pos -> [a, b]
 Text objects take an initial file position and transform it to a range
 where the former does not necessarily have to be contained in the latter.
 .
 All of the following text objects are implemented in an inner variant
 (prefixed with
 .Ic i )
 where the surrounding white space or delimiting characters are not part
 of the resulting range and a normal variant (prefixed with
 .Ic a )
 where they are.
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .
 .It Ic w
 word
 .
 .It Ic W
 WORD
 .
 .It Ic s
 sentence
 .
 .It Ic p
 paragraph
 .
 .It Ic [, ], (, ), {, }, <, >, \(dq, ', `
 block enclosed by these symbols
 .El
 .Pp
 Further available text objects include:
 .Bl -tag -width XXXXXXXXXX -compact
 .
 .It Ic gn
 matches the last used search term in forward direction
 .
 .It Ic gN
 matches the last used search term in backward direction
 .
 .It Ic al
 current line
 .
 .It Ic il
 current line without leading and trailing white spaces
 .El
 .
 .Ss Multiple Selections
 .
 .Nm
 supports multiple selections with immediate visual feedback.
 There always exists one primary selection located within the current
 view port.
 Additional selections can be created as needed.
 If more than one selection exists, the primary one is styled differently.
 .Pp
 To manipulate selections use in normal mode:
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .It Aq Ic C-k
 create count new selections on the lines above
 .
 .It Aq Ic C-M-k
 create count new selections on the lines above the first selection
 .
 .It Aq Ic C-j
 create count new selections on the lines below
 .
 .It Aq Ic C-M-j
 create count new selections on the lines below the last selection
 .
 .It Aq Ic C-p
 remove primary selection
 .
 .It Aq Ic C-n
 select word the selection is currently over, switch to visual mode
 .
 .It Aq Ic C-u
 make the count previous selection primary
 .
 .It Aq Ic C-d
 make the count next selection primary
 .
 .It Aq Ic C-c
 remove the count selection column
 .
 .It Aq Ic C-l
 remove all but the count selection column
 .
 .It Aq Ic Tab
 try to align all selections on the same column
 .
 .It Aq Ic Escape
 dispose all but the primary selection
 .El
 .Pp
 The visual modes were enhanced to recognize:
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .It Ic I
 create a selection at the start of every selected line
 .
 .It Ic A
 create a selection at the end of every selected line
 .
 .It Aq Ic Tab
 left align selections by inserting spaces
 .
 .It Aq Ic S-Tab
 right align selections by inserting spaces
 .
 .It Aq Ic C-a
 create new selections everywhere matching current word or selection
 .
 .It Aq Ic C-n
 create new selection and select next word matching current selection
 .
 .It Aq Ic C-x
 clear (skip) current selection, but select next matching word
 .
 .It Aq Ic C-p
 remove primary selection
 .
 .It Ao Ic C-u Ac Ao Ic C-k Ac
 make the count previous selection primary
 .
 .It Ao Ic C-d Ac Ao Ic C-j Ac
 make the count next selection primary
 .
 .It Aq Ic C-c
 remove the count selection column
 .
 .It Aq Ic C-l
 remove all but the count selection column
 .
 .It Ic +
 rotate selections rightwards count times
 .
 .It Ic -
 rotate selections leftwards count times
 .
 .It Ic _
 trim selections, remove leading and trailing white space
 .
 .It Ic o
 flip selection direction, swap cursor and anchor
 .
 .It Aq Ic Escape
 clear all selections, switch to normal mode
 .El
 .Pp
 In insert and replace mode:
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .It Aq Ic S-Tab
 align all selections by inserting spaces
 .El
 .Pp
 Selections can be manipulated using set operations.
 The first operand is the currently active selections while the second
 can be specified as a mark.
 For example,
 .Ic ' Ns Ar a Ns Ic \&|
 produces the union of the mark
 .Ar a
 and the current selection.
 Use of set operations without specifying a mark use the default mark as
 the first operand.
 .Pp
 .Bl -tag -width XXXXXXXXXX -compact
 .It Ic \&|
 set union
 .It Ic &
 set intersection
 .It Ic \e
 set minus
 .It Ic ~
 set complement
 .El
 .
 .Sh VI(M) COMMANDS
 .
 Any unique prefix can be used to abbreviate a command.
 .
 .Ss File and Window management
 .
 A file must be opened in at least one window.
 If the last window displaying a certain file is closed all unsaved changes are
 discarded.
 Windows are equally sized and can be displayed in rows (horizontally)
 or in columns (vertically).
 The
 .Aq Ic C-w
 .Ic h ,
 .Aq Ic C-w
 .Ic j ,
 .Aq Ic C-w
 .Ic k
 and
 .Aq Ic C-w
 .Ic l
 key mappings can be used to switch between windows.
 .Bl -tag -width indent
 .It Ic :new
 open an empty window, arranged as a new row (horizontally)
 .
 .It Ic :vnew
 open an empty window, arranged as a new column (vertically)
 .
 .It Ic :open Ns Oo Cm \&! Oc Op Ar file name
 open a new window, displaying file name if given
 .
 .It Ic :split Op Ar file name
 split window into rows (horizontally)
 .
 .It Ic :vsplit Op Ar file name
 split window into columns (vertically)
 .
 .It Ic :q Ns Oo Cm \&! Oc Op Ar exit code
 close currently focused window
 .
 .It Ic :qall Ns Oo Cm \&! Oc Op Ar exit code
 close all windows, terminate editor with exit code (defaults to 0)
 .El
 .Pp
 Commands taking a file name will invoke the
 .Xr vis-open 1
 utility, if given a file pattern or directory.
 .
 .Ss Runtime key mappings
 .
 .Nm
 supports global as well as window local run time key mappings which are
 always evaluated recursively.
 .
 .Bl -tag -width indent
 .It Ic :map Ns Oo Cm \&! Oc Ar mode Ar lhs Ar rhs
 add a global key mapping
 .
 .It Ic :map-window Ns Oo Cm \&! Oc Ar mode Ar lhs Ar rhs
 add a window local key mapping
 .
 .It Ic :unmap Ar mode Ar lhs
 remove a global key mapping
 .
 .It Ic :unmap-window Ar mode Ar lhs
 remove a window local key mapping
 .El
 .Pp
 In the above
 .Ar mode
 refers to one of
 .Ql normal ,
 .Ql insert ,
 .Ql replace ,
 .Ql visual ,
 .Ql visual-line
 or
 .Ql operator-pending ;
 .Ar lhs
 refers to the key to map and
 .Ar rhs
 is a key action or alias.
 An existing mapping may be overridden by forcing the map command by specifying
 .Cm \&! .
 .Pp
 Because key mappings are always recursive, doing something like:
 .Pp
 .Dl :map! normal j 2j
 .Pp
 will not work because it would enter an endless loop.
 Instead,
 .Nm
 uses pseudo keys referred to as key actions which can be used to invoke
 a set of available editor functions.
 .Ic :help
 lists all currently active key bindings as well as all available symbolic
 keys.
 .
 .Ss Keyboard Layout Specific Mappings
 .
 In order to facilitate usage of non-latin keyboard layouts,
 .Nm
 allows one to map locale specific keys to their latin equivalents by means of the
 .Pp
 .D1 Ic :langmap Ar locale-keys Ar latin-keys
 .Pp
 command.
 As an example, the following maps the movement keys in Russian layout:
 .Pp
 .Dl :langmap ролд hjkl
 .Pp
 If the key sequences have not the same length, the remainder of the longer
 sequence will be discarded.
 .Pp
 The defined mappings take effect
 in all non-input modes, i.e. everywhere except in insert and replace mode.
 .
 .Ss Undo/Redo
 .
 .Bl -tag -width indent
 .It Ic :earlier Op Ar count
 revert to older text state
 .It Ic :later Op Ar count
 revert to newer text state
 .El
 .Pp
 If count is suffixed by either of
 .Sy d
 .Pq days ,
 .Sy h
 .Pq hours ,
 .Sy m
 .Pq minutes
 or
 .Sy s
 .Pq seconds
 it is interpreted as an offset from the current system time and the closest
 available text state is restored.
 .
 .Sh SET OPTIONS
 .
 There are a small number of options that may be set
 .Pq or unset
 to change the editor's behavior using the
 .Ic :set
 command.
 This section describes the options, their abbreviations and their
 default values.
 Boolean options can be toggled by appending
 .Sy \&!
 to the option name.
 .Pp
 In each entry below, the first part of the tag line is the full name
 of the option, followed by any equivalent abbreviations.
 The part in square brackets is the default value of the option.
 .Bl -tag -width indent
 .It Ic shell Op Dq Pa /bin/sh
 User shell to use for external commands, overrides
 .Ev SHELL
 and shell field of password database
 .Pa /etc/passwd
 .
 .It Ic escdelay Op Ar 50
 Milliseconds to wait before deciding whether an escape sequence should
 be treated as an
 .Aq Cm Escape
 key.
 .
 .It Ic tabwidth , Ic tw Op Ar 8
 Display width of a tab and number of spaces to use if
 .Ic expandtab
 is enabled.
 .
 .It Ic autoindent , Cm ai Op Cm off
 Automatically indent new lines by copying white space from previous line.
 .
 .It Ic expandtab , Ic et Op Cm off
 Whether
 .Aq Ic Tab
 should be expanded to
 .Ic tabwidth
 spaces.
 .
 .It Ic number , Ic nu Op Cm off
 Display absolute line numbers.
 .
 .It Ic relativenumbers , Ic rnu Op Cm off
 Display relative line numbers.
 .
 .It Ic cursorline , Ic cul Op Cm off
 Highlight line primary cursor resides on.
 .
 .It Ic colorcolumn , Ic cc Op Ar 0
 Highlight a fixed column.
 .
 .It Ic horizon Op Ar 32768
 How many bytes back the lexer will look to synchronize parsing.
 .
 .It Ic theme Op Do default-16 Dc or Do default-256 Dc
 Color theme to use, name without file extension.
 Loaded from a
 .Pa themes/
 sub directory of the paths listed in the
 .Sx FILES
 section.
 .
 .It Cm syntax Op Cm auto
 Syntax highlighting lexer to use, name without file extension.
 .
 .It Cm showtabs Op Cm off
 Whether to display replacement symbol instead of tabs.
 .
 .It Cm shownewlines Op Cm off
 Whether to display replacement symbol instead of newlines.
 .
 .It Cm showspaces Op Cm off
 Whether to display replacement symbol instead of blank cells.
 .
 .It Cm showeof Op Cm on
 Whether to display replacement symbol for lines after the end of the file.
 .
 .It Cm savemethod Op Ar auto
 How the current file should be saved,
 .Ar atomic
 which uses
 .Xr rename 2
 to atomically replace the file,
 .Ar inplace
 which truncates the file and then rewrites it or
 .Ar auto
 which tries the former before falling back to the latter.
 The rename method fails for symlinks, hardlinks, in case of insufficient
 directory permissions or when either the file owner, group, POSIX ACL or
 SELinux labels can not be restored.
 .It Cm loadmethod Op Ar auto
 How existing files should be loaded,
 .Ar read
 which copies the file content to an independent in-memory buffer,
 .Ar mmap
 which memory maps the file from disk and uses OS capabilities as
 caching layer or
 .Ar auto
 which tries the former for files smaller than 8Mb and the latter for
 larger ones.
 WARNING: modifying a memory mapped file in-place will cause data loss.
 .It Ic layout Op Do v Dc or Do h Dc
 Whether to use vertical or horizontal layout.
 .It Cm ignorecase , Cm ic Op Cm off
 Whether to ignore case when searching.
 .It Ic wrapcolumn , Ic wc Op Ar 0
 Wrap lines at minimum of window width and wrapcolumn.
 .
 .It Ic breakat , brk Op Dq Pa ""
 Characters which might cause a word wrap.
 .El
 .
 .Sh COMMAND and SEARCH PROMPT
 .
 The command and search prompt as opened by
 .Ic \&: ,
 .Ic / ,
 or
 .Ic \&?
 is implemented as a single line height window, displaying a regular file
 whose editing starts in insert mode.
 .Aq Ic Escape
 switches to normal mode, a second
 .Aq Ic Escape
 cancels the prompt.
 .Aq Ic Up
 enlarges the window, giving access to the command history.
 .Aq Ic C-v
 .Aq Ic Enter
 inserts a literal new line thus enabling multiline commands.
 .Aq Ic Enter
 executes the visual selection if present, or else everything in the
 region spawned by the selection position and the delimiting prompt symbols
 at the start of adjacent lines.
 .
 .Sh CONFIGURATION
 .
 .Nm
 uses Lua for configuration and scripting purposes.
 During startup
 .Pa visrc.lua
 (see the
 .Sx FILES
 section) is sourced which can be used to set personal configuration options.
 As an example the following will enable the display of line numbers:
 .Pp
 .Dl vis:command('set number')
 .
 .Sh ENVIRONMENT
 .
 .Bl -tag -width indent
 .It Ev VIS_PATH
 The default path to use to load Lua support files.
 .It Ev HOME
 The home directory used for the
 .Ic cd
 command if no argument is given.
 .It Ev TERM
 The terminal type to use to initialize the curses interface, defaults to
 .Sy xterm
 if unset.
 .It Ev SHELL
 The command shell to use for I/O related commands like
 .Ic \&! ,
 .Ic > ,
 .Ic <
 and
 .Ic \&| .
 .It Ev XDG_CONFIG_HOME
 The configuration directory to use, defaults to
 .Pa $HOME/.config
 if unset.
 .El
 .
 .Sh ASYNCHRONOUS EVENTS
 .
 .Bl -tag -width indent
 .It Dv SIGSTOP
 Suspend editor.
 .It Dv SIGCONT
 Resume editor.
 .It Dv SIGBUS
 An
 .Xr mmap 2
 ed file got truncated, unsaved file contents will be lost.
 .It Dv SIGHUP
 .It Dv SIGTERM
 Restore initial terminal state.
 Unsaved file contents will be lost.
 .It Dv SIGINT
 When an interrupt occurs while an external command is being run it is terminated.
 .It Dv SIGWINCH
 The screen is resized.
 .El
 .
 .Sh FILES
 .
 Upon startup
 .Nm
 will source the first
 .Pa visrc.lua
 configuration file found from these locations.
 All actively used paths can be listed at runtime using the
 .Cm :help
 command.
 .Bl -bullet
 .It
 .Pa $VIS_PATH
 .It
 The location of the
 .Nm
 binary (on systems where
 .Pa /proc/self/exe
 is available).
 .It
 .Pa $XDG_CONFIG_HOME/vis
 where
 .Ev XDG_CONFIG_HOME
 refers to
 .Pa $HOME/.config
 if unset.
 .
 .It
 .Pa /etc/vis
 for a system-wide configuration provided by administrator.
 .It
 .Pa /usr/local/share/vis
 or
 .Pa /usr/share/vis
 depending on the build configuration.
 .
 .Pp
 When creating a new
 .Pa visrc.lua
 be sure to copy the structure from here.
 .El
 .
 .Sh EXIT STATUS
 .
 .Ex -std
 .
 .Sh EXAMPLES
 .
 Use
 .Nm
 as an interactive filter.
 .Pp
 .Dl $ { echo Pick your number; seq 1 10; } | vis - > choice
 .Pp
 Use the
 .Xr vis-open 1
 based file browser to list all C language source files:
 .Pp
 .Dl :e *.c
 .Pp
 Spawn background process and pipe range to its standard input:
 .Pp
 .Dl :> { plumber <&3 3<&- & } 3<&0 1>&- 2>&-
 .
 .Sh SEE ALSO
 .
 .Xr sam 1 ,
 .Xr vi 1 ,
 .Xr vis-clipboard 1 ,
 .Xr vis-complete 1 ,
 .Xr vis-digraph 1 ,
 .Xr vis-menu 1 ,
 .Xr vis-open 1
 .Pp
 .Lk http://doc.cat-v.org/bell_labs/sam_lang_tutorial/sam_tut.pdf "A Tutorial for the Sam Command Language"
 by
 .An Rob Pike
 .Pp
 .Lk http://doc.cat-v.org/plan_9/4th_edition/papers/sam/ "The Text Editor sam"
 by
 .An Rob Pike
 .Pp
 .Lk http://man.cat-v.org/plan_9/1/sam "Plan 9 manual page for sam(1)"
 .Pp
 .Lk http://doc.cat-v.org/bell_labs/structural_regexps/se.pdf "Structural Regular Expressions"
 by
 .An Rob Pike
 .Pp
 .Lk http://pubs.opengroup.org/onlinepubs/9699919799/utilities/vi.html "vi - screen-oriented (visual) display editor"
 .St -p1003.1
 .
 .Sh STANDARDS
 .
 .Nm
 does not strive to be
 .St -p1003.1
 compatible, but shares obvious similarities with the
 .Nm vi
 utility.
 .
 .\" .Sh HISTORY
 .\" TODO something about vi(m) and sam history
 .
 .Sh AUTHORS
 .
 .Nm
 is written by
 .An Marc André Tanner Aq mat at brain-dump.org
 .
 .Sh BUGS
 .
 On some systems there already exists a
 .Nm
 binary, thus causing a name conflict.